Refrigeration system for an ice skating rink

ABSTRACT

A refrigeration system for an outdoor ice skating rink includes a first heat exchanger that has a first conduit therein and is located outdoors. The first conduit has a first inlet and a first outlet and is configured to discharge heat to the outdoor ambient air. The refrigeration system includes a second heat exchanger that has a second conduit therein, and is in thermal communication with water in the ice skating rink. The second conduit has a second inlet and a second outlet and is configured to absorb heat from the water. The second outlet is in fluid communication with the first inlet via a warm-side conduit. The first outlet is in fluid communication with the second inlet via a cold-side conduit. One or more conveying devices are located in a closed loop that includes the first and second conduits, the warm-side conduit, and the cold-side conduit.

CROSS REFERENCE TO RELATED APPLICATION

This nonprovisional application claims the benefit of U.S. Provisional Application No. 63/299,457, filed on Jan. 14, 2022, the content of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention is directed to a refrigeration system for an ice skating rink that employs cold ambient air as the heat sink and utilizes a closed loop system for conveying a heat transfer fluid therein and that is configured to accelerate freezing of water in the ice skating rink.

BACKGROUND

Ice hockey and ice skating in general are increasingly popular in cold climates. The demand for ice time is so high compared with supply in many regions that teams and other clubs/groups must rent ice time during very early morning hours or very late nighttime hours. Many programs, especially those run by public high schools have been forced to reduce practice ice time hours or even eliminate entire programs due to increased costs to obtain ice time, particularly in view of reduced budgets.

Traditionally, hockey players and other skaters have used frozen lakes or ponds on which to skate during the winter months. In addition, families, towns, and other associations have flooded fields or parking lots to form ice on which to skate. Skating on lakes and ponds can be extremely dangerous. Also, flooding a permeable field or lot is not feasible in regions where the ice will melt and then refreeze throughout the winter, as the water will drain once the ice intermittently melts.

There are presently many complicated methods for constructing an outdoor ice rink. These usually involve constructing some sort of perimeter inside of which an impermeable liner is optionally laid. This open-top container is then partially filled with water, which can freeze into ice in the rough shape of an ice rink provided that the ambient temperature is below the freezing point of water for a sufficient period of time. In some locations, the temperature drops below freezing for a relatively short period of time such as during the nighttime hours. Moreover, the time to freeze the water in the ice skating rink is directly proportional to the water depth and total volume of water in the rink. In addition, the substrate that the rink is constructed on acts as a heat sink that can cause the ice to melt and/or to delay the freezing process.

There are various refrigeration systems that are designed to freeze water in an ice skating rink. However, the prior art systems generally employ refrigerant loops with compressors, vaporizers, condensers, and expansion valves. Such prior art systems utilize ammonia-based refrigerants, freon, R-22, R-404A, & R-134a freon replacements. However, such refrigerants can be hazardous to the environment. In addition, the prior art refrigeration systems for freezing water in an ice skating rink are very complex, difficult to operate, and typically require professional technicians to maintain and operate.

It is apparent from the above that there is a need for an improved refrigeration system that can be used with portable, free-standing outdoor skating rinks.

SUMMARY

The present invention according to an embodiment includes a refrigeration system for an outdoor ice skating rink which includes a first heat exchanger that has a first conduit therein and is located outdoors. The first conduit has a first inlet and a first outlet and is configured to discharge heat to the outdoor ambient air. The refrigeration system includes a second heat exchanger that has a second conduit therein, and that is in thermal communication with water in the ice skating rink. The second conduit has a second inlet and a second outlet and is configured to absorb heat from the water. The second outlet is in fluid communication with the first inlet via a warm-side conduit. The first outlet is in fluid communication with the second inlet via a cold-side conduit. One or more conveying devices (e.g., pumps) are located in a closed loop that includes the first and second conduits, the warm-side conduit and the cold-side conduit.

In some embodiments, the refrigeration system includes a convection device (e.g., fan or blower driven by a drive unit) that is in thermally conductive communication with the first conduit for accelerating discharge of heat from the first conduit.

In some embodiments, the fluid conveying device is located in the warm-side conduit and/or in the cold-side conduit.

In some embodiments, the ice skating rink includes an impermeable liner and the second conduit is positioned between the liner and a substrate upon which the ice skating rink is situated and/or above the liner and submerged in the water contained by the impermeable liner.

In some embodiments, the second conduit comprises a web structure connected to adjacent segments of the second conduit.

In some embodiments, the impermeable liner and the second conduit are integrally formed with one another.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of the refrigeration system of the present invention shown installed in an ice skating rink;

FIG. 2 is a cross sectional view of the ice skating rink taken across section 2-2 of FIG. 1 according to an embodiment;

FIG. 3 is a cross sectional view of the ice skating rink taken across section 2-2 of FIG. 1 according to another embodiment;

FIG. 4 is a perspective view of a conduit of the refrigeration system of FIG. 1 shown with a web structure therein;

FIG. 5 is a perspective view of a liner for an ice skating rink with a heat exchanger conduit formed integrally with the liner;

FIG. 6 is a top view of a portion of the liner of FIG. 5 ;

FIG. 7 is a top schematic view of an ice skating rink having tension members that convey a heat transfer fluid therethrough; and

FIG. 8 is a perspective cross-sectional view of a tension member of FIG. 7 .

DETAILED DESCRIPTION

As shown in FIG. 1 , a refrigeration system for an outdoor ice skating rink 10 is generally designated by the numeral 100. The refrigeration system 100 includes a first heat exchanger 20 (e.g., an automotive radiator) that has first conduit 22 therein. The first heat exchanger 20 is located in outdoor ambient air. The first conduit 22 has a first inlet 24 and a first outlet 26. The first heat exchanger 20 is configured to discharge heat to the outdoor ambient air. The refrigeration system 100 includes a second heat exchanger 30 that has a second conduit 32 therein. The second conduit 32 is in thermal communication with water in the ice skating rink 10. The second conduit 32 has a second inlet 34 and a second outlet 36. The second heat exchanger 30 is configured to absorb heat from the water. As used herein, the term “conduit” refers to any fluid transfer means known in the art, including but not limited to pipes, tubes, coils, channels, ducts, culverts, troughs, etc.

As shown in FIG. 1 , the second outlet 36 is in fluid communication with the first inlet 24 via a warm-side conduit 40. The first outlet 26 is in fluid communication with the second inlet 34 via a cold-side conduit 50. The refrigeration system 100 includes one or more fluid conveying devices 60, 60′ located in a closed loop which includes the first conduit 22, the second conduit 32, the warm-side conduit 40, and the cold-side conduit 50. The fluid conveying devices 60, 60′ are configured to circulate a heat transfer fluid (e.g., an anti-freeze mixture) in the closed loop.

As shown in FIG. 1 , a first fluid conveying device 60 is located in the cold-side conduit 50 and a second fluid conveying device 60′ is located in the warm-side conduit 40. The first fluid conveying device 60 has a suction side 60A that is in fluid communication with the first outlet 26 via a first section of the cold-side conduit 50. The first fluid conveying device 60 has a discharge side 60B that is in fluid communication with the second inlet 34 via a second section of the cold-side conduit 50. The second fluid conveying device 60′ has a suction side 60A′ that is in fluid communication with the second outlet 36 via a first section of the warm-side conduit 40. The second fluid conveying device 60′ has a discharge side 60B′ that is in fluid communication with the first inlet 24 via a second section of the warm-side conduit 40. While the refrigeration system 100 is shown and described as have the first fluid conveying device 60 and the second fluid conveying device 60′, the present invention is not limited in this regard as only one fluid conveying device or more than two fluid conveying devices may be employed in either of the warm-side conduit 40 or the cold-side conduit 50.

In some embodiments the fluid conveying device 60, 60′ is a pump that has a first drive unit 65, 65′, respectively, attached thereto for causing the pump to operate. In some embodiments, the first drive units 65, 65′ are connected to a power supply 83, 83′, respectively, such as a battery, portable generator, or alternating current line supply.

In some embodiments, the refrigeration system 100 includes a convection device 70 (e.g., a fan or blower 71 driven by a second drive unit 72) that is in thermally conductive communication with the first conduit 22 for accelerating discharge of heat from the first conduit 22. In some embodiments, the second drive unit 72 is connected to a power supply 73, such as a battery, portable generator, or alternating current line supply. The convection device 70 conveys cold ambient air that is at a temperature less that zero degrees Celsius (less than 32 degrees Fahrenheit) over outside surfaces of the first conduit 22 thereby decreasing the temperature of the heat transfer fluid flowing through the first conduit 22.

As shown in FIG. 1 , in some embodiments, the refrigeration system 10 includes a control system 90 (e.g., a computer processor/controller) that is in communication with a temperature sensor 92 located in the ice skating rink 10 and an ambient air temperature sensor 94. The control system 90 is configured to control the convection device 70 and the fluid conveying devices 60, 60′ to ensure the water in the ice skating rink 10 is kept frozen and at the coldest temperature possible. While one temperature sensor 92 and one ambient air temperature sensor 94 are shown and described, the present invention is not limited in this regard as more than one of such temperature sensors may be employed.

As shown in FIG. 2 , the ice skating rink 10 has a perimeter wall 13 positioned on a substrate 14 (e.g., a lawn, a cleared soil area, an asphalt surface) and extending around a skating area of the ice skating rink 10. An impermeable liner 11 extends across the substrate 14 and is draped over the perimeter wall 13. The second conduit 32 is positioned between the liner 11 and a substrate 14 upon which the ice skating rink 10 is situated. Water 15 is contained by the liner 11 within the perimeter wall 13. The second inlet 34 and the second outlet 36 are shown extending through the perimeter wall 13. However, in some embodiments, the second inlet 34 and the second outlet 36 travel under the perimeter wall 13.

The ice skating rink shown in FIG. 3 is similar to the ice skating rink of FIG. 2 except that the second conduit 32 is positioned above the liner 11 and submerged in the water 15 contained by the impermeable liner 11, and the second inlet 34 and the second outlet 36 travel over the top of the perimeter wall 13 and liner 11.

As shown in FIG. 1 , the second conduit 32 is configured in a serpentine shape between the second inlet 34 and the second outlet 36. As shown in FIG. 4 , a portion of the second conduit 32 is illustrated and shows that the second conduit has a web structure 39 connected to adjacent sections of segments of the serpentine shaped second conduit 32. The second conduit 32 has flow passages with a flat cross-section having a thickness T. The heat transfer fluid flows through the second conduit 32 as indicated by the arrows F. While the second conduit 32 is shown and described as having a serpentine shape, the present invention is not limited in this regard as other flow patterns are included in the present invention such as flow patterns that selectively cool portions of the ice skating rink before other portions, such as but not limited to cooling portions of the ice skating rink 10 that are exposed to sun light before cooling portions that are in the shade and cooling portions of the ice skating rink 10 located closer to the perimeter wall 13 before cooling more inwardly located portions of the ice skating rink 10 that are located more centrally and farther away from the perimeter wall 13.

As shown in FIGS. 5 and 6 , in some embodiments, the second conduit 32 is integrally formed with the liner 11.

In some embodiments, the heat transfer fluid is a liquid that has an anti-freeze therein to lower the freezing point of the heat transfer fluid. The refrigeration system does not employ any freon refrigerant and does not require a compressor and expansion valve typically used in refrigeration systems. The anti-freeze is an environmentally friendly substance such as a vegetable based anti-freeze that includes vegetable extracts that are non-toxic, biodegradable, and more thermally efficient than Propylene Glycol based coolants.

As shown in FIG. 7 , the ice skating rink 10 has a plurality of perimeter walls 13. Opposing sections of the perimeter walls 13 are connected to one another by a respective one of a plurality of tension member 5V, 5H. Each of the tension members 5V, 5H has a flow passage 55F therein for conveying the heat transfer fluid (see FIG. 8 ). The plurality of tension members 5V, 5H cooperate with one another to form the second conduit 32 of the second heat exchanger 30. The second inlet 34 of the second heat exchanger 30 branches off into a first header 34H1 which is removably connected to an inlet side of each of the tension members 5V. A second header 34H2 is removably connected to an outlet side of each of the tension members 5V. The second header 34H2 is in fluid communication with a third header 34H3 via a branch line 39. The third header 34H3 is removably connected to an inlet side of each of the tension members 5H. A discharge header 36H is removably connected to an outlet side of each of the tension members 5H. The discharge header 36H is in fluid communication with the second outlet 36 of the second heat exchanger 30. Thus, the flow of the heat transfer fluid is from the first header 34H1 to the second header 34H2 via the tension members 5V; from the second header 34H2 to the third header 34H3 via the branch line 39; and from the third header 334H3 to the discharge header 36H via the tension members 5H, in a cross flow pattern. While a cross flow pattern is shown and described, the present invention is not limited in this regard as other flow patterns are included in the present invention such as those that preferentially cool outer sections of the ice skating rink before inner sections.

As shown in FIG. 8 , a cross section of one of the tension members 5V, 5H is shown with a web portion 55W and a flow passage portion 55F.

Although this invention has been shown and described with respect to the detailed embodiments thereof, it will be understood by those of skill in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed in the above detailed description, but that the invention will include all embodiments falling within the scope of the appended claims. 

What is claimed is:
 1. A refrigeration system for an outdoor ice skating rink, the refrigeration system comprising: a first heat exchanger having first conduit therein, the first heat exchanger being located in outdoor ambient air, the first conduit having a first inlet and a first outlet, the first heat exchanger being configured to discharge heat to the outdoor ambient air; a second heat exchanger having a second conduit therein, the second conduit being in thermal communication with water in the ice skating rink, the second conduit having a second inlet and a second outlet, the second heat exchanger being configured to absorb heat from the water; the second outlet being in fluid communication with the first inlet via a warm-side conduit; the first outlet being in fluid communication with the second inlet via a cold-side conduit; and at least one fluid conveying device located in a closed loop comprising the first conduit, the second conduit, the warm-side conduit and the cold-side conduit, the at least one fluid conveying device being configured to circulate a heat transfer fluid in the closed loop.
 2. The refrigeration system of claim 1, further comprising a convection device in thermally conductive communication with the first conduit for accelerating discharge of heat from the first conduit.
 3. The refrigeration system of claim 1, wherein the at least one fluid conveying device is located in at least one of: (a) the warm-side conduit; and (b) the cold-side conduit.
 4. The refrigeration system of claim 1, wherein the at least one fluid conveying device comprises a pump driven by a first drive unit.
 5. The refrigeration system of claim 2, wherein the convection device comprises a fan or blower driven by a second drive unit.
 6. The refrigeration system of claim 1, wherein the ice skating rink comprises an impermeable liner, and the second conduit is positioned between the liner and a substrate upon which the ice skating rink is situated.
 7. The refrigeration system of claim 1, wherein the ice skating rink comprises an impermeable liner, and the second conduit is positioned above the liner and submerged in the water contained by the impermeable liner.
 8. The refrigeration system of claim 1, wherein the second conduit comprises a web structure connected to adjacent sections of segments of the second conduit.
 9. The refrigeration system of claim 1, wherein the second conduit comprises a serpentine shape with a flat flow passage cross-section.
 10. The refrigeration system of claim 1, wherein the ice skating rink comprises an impermeable liner and the second conduit is integral with the liner. 